Hi All,

I received this today from anonymous authors.

PACIFIC-ANTARCTIC RIDGE FAR-FIELD AFTERSHOCK FORECAST SEPTEMBER 2, 2001

An earthquake of Ms~6.5 occurred on the morning (UT) of September
2 along the Pacific-Antarctic Ridge. The event occurred in an area which was
under a seismic watch resulting from the strong X5.3 flare on 25 August.
There have been 7+ days since that event, time enough for triggering to occur
at mid-ocean ridge regions. A Ms 5.9 had occurred only hours before
in the mid-ocean ridge south of India. Warnings had been posted to this
board regarding possible strong mid-ocean ridge activity since shortly
after the flare occurred. The strongest effects are commonly 4-6 days after
flares, so this event occurred slightly later than expected.
This earthquake occurred 34.5 degrees from the New Zealand mainshock
(Me 7.2, 21 August, 2001), and should be considered a far-field
aftershock of that event as it was in an area and distance forecast
for far-field triggering:

"34-36 degrees:
43-45 degrees: Pacific-Antarctic Ridge"

It is the second strong earthquake in a month on the Pacific-
Antarctic Ridge. The first was a Me 6.6 that occurred on August 6, 2001
about 1000 km to the east of this event and had an extensive far-field
aftershock sequence. Because of that sequence, a far-field aftershock
forecast for today's event is being produced even though it is too
small to normally generate such a forecast.
This was the largest event within 200 km of the epicenter since
January 1951 when a Ms 6.9 occurred, and the second largest in this area
in recorded history. The largest event was the 1951 event. Events of
similar magnitude (Ms 6.5) occurred on May 25, 1984 and March 10, 1932.
It is alos the largest event in the region within 500 km of the epicenter
since May 20, 1953 when a Ml 7.3 occurred about 300 km to the west
of today's event although several events of similar size have occurred:
Aug. 24, 1970 (Ms 6.5); Sept 18, 1973 (Ms 6.4); Apr 18, 1993 (Ms 6.4).
This is the first event of Ms>=6 within 500 km of the epicenter since
October 11, 1998 when a Ms 6.3 occurred about 300 km to the west.

Current parameters for this event are (times are UT) compared
with forecast parameters:

O: 02Sep2001 10:06:54 54.4S 136.8W MS=6.5 GSR PACIFIC-ANTARCTIC RIDGE
O: 02Sep2001 10:06:51 54.5S 136.5W MW=6.2 NEIS PACIFIC-ANTARCTIC RIDGE

Postings had identified this area as a possibility for
a large event following the X5.3 solar flare as follows:

"This is the largest flare since April, so batten down the hatches. Seismicity
could skyrocket in a couple of days, at least according to some theorists. A
geomagnetic storm began shortly after the flare. This is known as SFE (solar
flare effects). The particle stream should arrive in the next 2-5 days.
Historically, large (M>=7) and great (M>=8) earthquakes occur 4-5 days
after strong flares in REGIONS NEAR THE GEOMAGNETIC POLES and along the
geomagnetic equator. This includes places like northern Canada, Alaska,
Vancouver Island, New Zealand, etc." 25 August, 2001

and

" The strong sequence of mid-ocean ridge events which began after the flare,
however is expected to continue for at least two more days. Mid-ocean ridge
events have thus far occurred South of Africa, in the south and north
Mid-Atlantic Ridges, in the region near Svalbard, in the Gulf of Aden, the
East Africa Rift valley, the Arctic ocean, South of Panama, east of Australia,
the East Pacific Rise and in the South Indian Ocean. All these events have
occurred in the 4 days since the flare. This is a considerable increase in
mid-ocean ridge seismicity over background levels, but is typical of
increased oceanic activity following major solar flares." Sent August 29, 2001

The event is likely to have had a strike-slip mechanism. This
type of event seldom produces tsunamis, so a tsunami is unlikely
except as a landslide tsunami in local areas.

Although a Ms 6.5 earthquake is normally too small to produce
wide-spread far-field triggering, regional triggering is possible
especially when the event occurs in an unusual position with
resulting horizontal motions of the earth as did this one.

Following is a preliminary far-field forecast from this event.
Areas within 36 degrees are expected to see maximum magnitudes increase
by 0.3-0.6 units, at distances farther than this, increases in
maximum magnitude are expected to be about 0.4 units or less.
Seismicity is expected to increase in these areas for the next
10 days (i.e. through 12 September, 2001)

0-5 degrees: Local Pacific-Antarctic Ridge events (Classical aftershock zone)
9-10 degrees: Pacific-Antarctic Ridge events (around 120W and 155W)
17-19 degrees: East Pacific Rise near 47S
34-36 degrees: New Zealand aftershock zone (around 37S 179-180W)
Alpine fault zone, New Zealand (strikes this area with
wave front parallel to the fault, this is a situation where
a moderate event can be triggered if strain conditions in this
region are otherwise favorable). The same situation applies to
the Macquarie ridge south of New Zealand. This entire area
should be under seismic watch for the next 5-10 days.
43-45 degrees: South of the Loyalty Islands, Samoa, So. Chile (about 39S)
East Pacific Rise (about 15 S)
59-61 degrees: Vanuatu Isl. (about 13S), East Pacific Rise (about 5S)
Off Coast of So. Peru - (like the Alpine fault in New Zealand,
the wavefronts approach this region parallel with the subduction
zone from about 21 S to about 15 S, a strong earthquake could
be triggered under these circumstances).
71-73 degrees: Ecuador, Hawaii, New Britain
101-105 degrees***: No. Georgia, Yellowstone, Idaho, Oregon-Washington
border area, Volcano Isl., Mindanao, Sumatera, Central Mid-Atlantic
ridge (10N-1S, 20-35W)
142-146 degrees: Iceland, Spain, Pakistan, SE Iran, portions of
Sinkiang, China, W. Nepal.
176-180 degrees: Aseismic area 55N 44E near Moscow, Russia

Most likely areas to be affected are 101-105 degrees distance and
at 142-146 degrees away from the epicenter.

Previous history

Aug 2, 1930 57S 135W Mw 6.5?

==> AUG 4, 1930 Peru 8S 70W Ms 6.5
==> AUG 5, 1930 Off Coast No. Calif. 40N 127W Ms 5.3
==> AUG 5, 1930 Southern California 34.5N 119.5W Ms 5.0
The wavefront is parallel with the bend in the San Andreas
in Southern California. This can produce moderate earthquakes
in this area during the 10 days after shocks in this area of the
Pacific Antarctic Ridge.
==> AUG 9, 1930 South of Spain 34N 5W Ms 5.6
==> AUG 13, 1930 New Madrid, MO, 36N 89W Ml 3.0
==> AUG 12, 1930 Coso Junction CA, 36N 118W Ml 4.0
==> AUG 17, 1930 Honshu, Japan 35N 140E Ms 6.0

March 10, 1932 55S 135W Mw 6.5

==> March 10, 1932 Oaxaca Mexico, 18N 95W Ms 5.5
==> March 13, 1932 Santa Maria, CA 34N 120W Ml 3.5
==> March 14, 1932 Gulf of California 22N 109W Ms 6.0
==> March 14, 1932 Venezuela 8N 71W Ms 6.7
==> March 14, 1932 Guam 11N 144E Ms 6.3
==> March 15, 1932 Caucasus 40N 44E Ms 5.6
==> March 18, 1932 So. Indian Ocean 17S 66E Ms 6.0
==> March 18, 1932 Iceland 64N 22W Ml 4+ swarm
==> March 19, 1932 Mariana Islands 15N 147E Ms 6.7
==> March 19, 1932 New Britain 3S 152E Ms 6.5
==> March 23, 1932 East Pacific Rise 37S 99W Ms 6.0

Jan 20, 1940 55S 133W Ms 6.8

==> JAN 21, 1940 Kermadec Isl. 32S 178W Ms 6.3
==> JAN 24, 1940 North Isl. N.Z. 39S 175E Ml 4.5
==> JAN 26, 1940 Coso Junction region, CA 36N 118W Ml 3.5
==> JAN 26, 1940 Hindu Kush 36N 71E Ms 5.8
==> JAN 26, 1940 South of Honshu 27N 132E Ml 6.5
==> JAN 28, 1940 Alaska/Yukon border 62N 137W Ml 5.4
==> JAN 28, 1940 So. California 34N 118.2W Ml 3.0
==> JAN 28, 1940 New England 41N 71W Ml 4.3
==> JAN 30, 1940 Peru 12S 71W Ms 5.6

Jan 23, 1951 (Ms 6.9 at 56S 136W)

==> Jan 23, 1951 Utah 39N 111W Ml 3.7
==> Jan 24, 1951 So. California 33N 116W Ml 6.4
==> Jan 26, 1951 New England 41N 72W Ml 3.3
==> Jan 26, 1951 Mammoth Lakes 37N 118W Ml 3.5
==> Jan 27, 1951 South Isl. N.Z. 43S 173E Ml 5.3
==> Jan 28, 1951 Taiwan 23N 122E Ms 6.0
==> Jan 28, 1951 Southern California 33N 119W Ml 3.1
==> Jan 29, 1951 Off Coast of Oregon 43N 128W Ml 5.0
==> Jan 29, 1951 Coso Junction CA 36N 118W Ml 3.2
==> Jan 30, 1951 Oaxaca Mexico 16N 98W Ms 6.4
==> Feb 02, 1951 Sakhalin 47N 142E Ms 5.5

Aug 24, 1970 (Ms 6.5 at 56S 142W)

==> Aug 26, 1970 Southern California 34N 119W Ml 4.3
==> Aug 25, 1970 Volcano Islands 22N 142E Mb 5.4
==> Aug 26, 1970 Luzon, Philippines 16N 120E Mb 5.4
==> Aug 27, 1970 Samoa 15S 173W Ms 6.0
==> Aug 27, 1970 Oaxaca, Mexico, 15N 95W Ms 6.0
==> Aug 28, 1970 New Britain 5S 153E Ms 6.5
==> Aug 28, 1970 So. of Kermadec Isl. 33S 179W Ms 5.6
==> Aug 28, 1970 Off Coast No. Calif. 42N 126W Ms 4.6
==> Aug 30, 1970 Central California . 37N 121W Ms 4.6
==> Aug 30, 1970 Okhotsk, Russia . 52N 151E Ms 7.2
==> Sep 01, 1970 Mariana Islands 18N 147E Ms 6.5
==> Sep 01, 1970 No. Montana 48N 114W Ml 4.0
==> Sep 03, 1970 Vanuatu 17S 167E Ms 6.1

May 25, 1984 (Ms 6.3 at 55S 135W)

==> May 26, 1984 So. Indian Ocean 43S 38E Ms 6.4
==> May 26, 1984 Santa Cruz Isl. 10S 164E Ms 6.2
==> May 29, 1984 Wyoming, 44N 105W Ml 5.0
==> May 30, 1984 New Britain 5S 151E Ms 6.2
==> Jun 02, 1984 So. Island, N.Z. 42S 173E Mb 4.3
==> Jun 02, 1984 Washington state 47N 122W Ml 3.5

Apr 18, 1993 (Ms 6.4 at 56S 139W)

==> Apr 19, 1993 Halmahera 4N 128E Ms 6.7
==> Apr 20, 1993 So. California 34N 119W 3.0
==> Apr 20, 1993 Macquarie Isl. 54S 144E Ms 5.7
==> Apr 20, 1993 Fiji Isl. 20S 178W Mw 5.8
==> Apr 22, 1993 So. Sumatera 4S 102E Ms 5.7
==> Apr 22, 1993 Kodiak Island 56N 154W Mb 5.4
==> Apr 22, 1993 Baja California 33N 115W Ml 3.7
==> Apr 25, 1993 Samoa 15S 173W Ms 5.7
==> Apr 25, 1993 Arizona 35N 112W Mb 5.0
==> Apr 28, 1993 New Madrid, MO. 36N 89W Ml 3.5
==> Apr 28, 1993 Arizona 35N 112W Mb 5.5

Oct 11, 1998 (Ms 6.3 at 56S 142W)

==> Oct 13, 1998 Honshu, Japan 40N 143E Mb 5.4
==> Oct 14, 1998 Western Greenland Mb 5.1
==> Oct 14, 1998 New Britain 6S 151E Ms 5.8
==> Oct 15, 1998 Baja California 32N 115W Ml 4.3
==> Oct 14, 1998 So. Chile 41S 73W Mb 4.4
==> Oct 15, 1998 Northern California 41N 124W Mw 4.3
==> Oct 15, 1998 Vanuatu 13S 167E Mb 5.0
==> Oct 16, 1998 Myanmar 23S 94E Mb 5.2
==> Oct 16, 1998 So. Chile 38S 71W Mb 4.2
==> Oct 17, 1998 Unimak, Alaska 54N 163W Ml 5.2
==> Oct 17, 1998 Marianas 19N 145E Ms 5.7
==> Oct 18, 1998 Volcano Islands 24N 141E Mb 5.5
==> Oct 20, 1998 South Island, N.Z. 43S 170E Mw 5.4
==> Oct 20, 1998 Baja California 32N 115W Ml 3.9
==> Oct 21, 1998 Virginia 37N 78W Ml 3.8
==> Oct 21, 1998 Washington-Oregon border 46N 122W Ml 3.2
==> Oct 21, 1998 No. California 40N 121W Ml 4.5

SUMMARY OF EXPECTED FAR-FIELD EVENTS

Areas where the wave-front is parallel to the local
faulting have experienced large events following earthquakes
in this region of the Pacific-Antarctic Ridge. These
areas include the Central American/Mexican subduction
zone, the portion of the San Andreas running from about
116W to 119W in So. California, the Mendocino escarpment
area off the Coast of No. California and the Alpine fault in New Zealand
and the Macquarie Islands south of New Zealand.
These areas should be on seismic watch for the next 10 days. Earthquakes
of Ms>5.4 are possible in these areas.
Regions at distances where seismicity is expected
to increase often do show moderate to large earthquakes
following events in this area of the Pacific-Antarctic
Ridge. Some of these which have a record of strong far-field
seismicity include the subduction zone south of Mexico,
the Mariana Islands, Kermadecs, and New Britain.
In the United States seismic events in Southern California
ond off the coast of Northern California in the Mendocino area
often follow earthquake in this area of the Pacific. There was
a Mb 6.4 in Baja California and a Ms 6.0 in the Gulf of California
along with events of Ml>3 associated with each of the previous
Ms>=6.3 events in this area of the South Pacific. The Coso
Junction (CA) region appears particularly sensitive having
experienced locally significant earthquake on 4 different
occasions (Ml 4.0, 3.5, 3.2, 3.8).
Other areas in the U.S. which have previously expeienced
activity after such So. Pacific events include the region of
So. Washington/No. Oregon, Arizona, and New England (near 41N 71W
Massachusetts). New Madrid has been activated on two occasions
(36N 89W, Ml 3.0, 3.5).

Areas where an event of Mb>=5.5 is most likely in the next 10 days:
(Expected maximum magnitudes increase by 1.0 units)
New Britain
Volcano/Mariana Islands
Mexico/Oaxaca
Samoa/ So. Tonga Islands

Areas where an event of MB<=5.0 is likely in the next 10 days:
(Expected maximum magnitudes increase by 0.6 units)
Honshu (36N 141E)
Peru
Sakhalin, Russia (47N 142E)
Kermadec Islands (34S 178W)
Macquarie Islands region
South Island, New Zealand to Cook Strait
Vanuatu Islands (13-17S, 167E)
Southern Chile (37-43S, 75-70W)

Local areas in the U.S. which may experience a regionally
significant or moderate quake or increased activity:
(Expected maximum magnitudes increase by 0.5 units)

Washington/Oregon border area
Region off the Coast of No. California/Oregon
Southern California 115-119.5W 32-35N
Coso Junction, CA
Kodiak Island, Alaska
A section between 34-36N from Virginia, New Madrid, Arizona,
Southern California